Talk tequila:

Tequila sips:

When the agave shortage hit Mexico, causing havoc in the tequila industry, local South African businessmen formed Reinet Distillers to produce their own, home-grown version of tequila. However, while the owners struggled to unlock Mexico’s tequila-making traditions, they experienced technical problems in their factory. Reinet Distillers closed without making a single shot of alcohol.

Donations

To help me defray costs of maintaining this site and my forum, I
would very much appreciate your donation. Use the Paypal button
above (or make any online payment service payment through Paypal
directly to me at
ichadwick@rogers.com) Cheques and
money orders are also accepted (just be very careful when
sending the latter... always use registered mail or courier).
Contact me for mail information.

Cooking & Milling the Agave Heads

Once the piņas have been harvested, they are usually split into
halves or even quarters, depending on their size. These are carefully
stuffed by hand into the ovens for cooking.

The
top (corta) of the head is cut out before loading - this is the place where the quiote emerges
and producers say it makes the tequila bitter if left intact.

Before the late 19th century, piņas were cooked in rock-lined pits in
the ground, like agave for mezcal is still cooked today. However,
increasing demand for tequila meant increased demand for wood, and
Jalisco's forests were soon denuded. Distillers turned to above-ground
ovens and coal- or gas-fired heating.

In 1864, Manuel Payno published his work Memoria sobre el maguey
mexicano y sus diversos productos. In it he described a transitional
stage horno as: "similar to the kilns for baking bricks or limestone."
He then described the cooking process:

When the oven is full, a fire is lit in the lower part,
and once it is burning brightly, the opening is blocked with agave
leaves and earth, so as to avoid any heat loss. This system is highly
economical with respect to fuel, for as soon as the logs catch fire, the
workers begin blocking the upper part with agave leaves, and when the
heat reaches that part, they promptly shovel earth over the whole thing,
so the mezcal remains insulated for as long as it takes to bake through
and through.

Cooking the agave is a required step for tequila because the heat gently and
slowly transforms the agave's natural carbohydrates and starches into fermentable sugars.

All cooking ovens today are steam-heated, above-ground ovens that use
pressurized steam to cook the agave. Older ovens are stone or
brick-lined, newer ovens are stainless steel autoclaves.

Farmers who sell piņas by weight may leave on more of the penca, or
leaf, while
those paid daily wages by the producer are more likely to cut them off
closer to the piņa.

It takes about 7 kilograms of piņa to produce 1 litre of 100% agave tequila - which means the average piņa can make
2-5 litres. It has also been said that small distillers may simply purchase agave syrup to
ferment, without any of the intervening processes, but this author has
yet to see this happen. Given the glut of agave at present, this would
seem unnecessary.

Some distillers will 'pre-cook' the piņas to rid them of external
waxes and solids that may be retained in the leaf (penca) at its base. These can make a
bitter or unpleasant juice. These distillers will let this 'bitter
honey' collect for a couple of hours in the oven, then drain it off.

The steam-injected autoclaves used in modern
distilleries also wash away any external materials from the piņas.

The
traditional stone or brick oven is called a horno - hence the name of Sauza's
Hornitos.
Traditional distillers (tequilleros) let the piņas soften in the steam
ovens or for 50-72 hours at moderate heat. This bakes the agave to
process its natural juices at
around 140-185 degrees F (60-85C - others may be lower: 135-145F;
57-62C). A few will cook them at higher temperatures: 175-200 F(
80-95C).

This slow-bake process softens the fibres and
helps keep the agave from caramelizing, which can add darker and bitter flavours to the juice and reduces the agave sugars. Baking in
sealed ovens also
helps retain more of the natural agave flavours.

The moderate heat in the oven breaks apart the long starch molecules
into shorter, fermentable sugar molecules. Too high and the sugars
caramelize. Too low and the molecules don't break apart.

As the agave heads cook, they release moisture and change colour, from
white to dark yellow to brown and rusty orange.

The juices released from the head collect at the
bottom of the oven. Most ovens have a valve system that allows producers
to drain away the first couple of hours of liquid - called the bitter
honey because it is full of impurities and
waxes from the plant - and
again at the end of the distillation, when the sweet liquid is added to
the fermenting tank.

Here's where mezcal and
tequila part ways: mezcal piņas are baked slowly in underground pits,
rather than steamed. Mezcal agave take on the aromas and flavours
imparted by the burning wood and the earth cover. Tequila agave have no
such influences.

Many large distillers prefer to cook their piņas faster in efficient
steam autoclaves and pressure cookers in as little as a single day (12-18
hours). These big pressure cookers can cook the agave at much higher
temperatures than the traditional oven.

No matter which method is used ,the baking process turns the complex carbohydrates into
fermentable sugars and softens the piņa so they
can easily release their
juice.

Fresh from the oven, the piņas taste a bit like a sweet potato or
yam, sometimes a little like burnt honey, with a mild tequila aftertaste.

In traditional distilleries, the
piņas are allowed to cool for another 24-36 hours after steaming, then
they are mashed to separate the pulp (bagazo or bagasse) from the juice
(although some traditional distillers keep them together during the
fermenting).

Crushing the baked agave to extract the juices

Originally, the manufacturers beat the piņas with
large wooden mallets to break them
up once they were soft and cool, then stomping on them like grapes to
get the juices out..

Manuel Payno's work of 1864 describes the process:

After this the cooked hearts are taken to the crusher
where they are broken up, mashed and squeezed by a variety of imperfect
methods. The most common approach is to beat the material with huge
wooden clubs, before trampling it to release the juice.

Producers soon moved to the tahona, a giant
grinding wheel that can weigh up to two tons, operated by mules, oxen or
horses (nowadays more likely by a tractor) and pulled in a circle in a
cobble-stone-lined pit. Some distillers still use a tahona, but few use it exclusively.

As the tahona crushes the agave, the fibres are separated from the
juices.
Eventually the workers have to get into the pit and use
pitchforks to remove the fibres, before the juices are drained off. The
waste fibre is called bagaso, and may be used for compost, or fuel, and
rarely for paper or textiles.

Some producers will take some of the crushed fibre from the tahona pit
and add it back to the fermentation tank, to give the wort more agave
flavour.

Modern distilleries use a
mechanical crusher, or shredder, like a giant wood-chipping machine to
process out the waste bagazo (the agave fibres, usually given away as animal food or
used as
fertilizer on the fields). This machine was first introduced to mill
sugar cane for rum and aguardiente production.

Using one of these methods, the piņas are minced, washed
with water and
strained to remove the juices (called aquamiel, or honey water), them
mixed with water in large vats. Many of these crushers process the fibres four times in a single line, separating all available juice from
the fibres.

Some of these shredding and crushing machines are smaller - the crusher
at Partida is a one-step machine. Each step presses and washes the
agave, adding more water to the juice and diluting it.

Some distillers have experimented with other technology, including a
grape-crushing machine, imported from France, at Tequilana. To date, no technology has
proven superior to that already used to crush and shred the cooked
agave, but the search is not over.

The leaves of the blue agave plant, heretofore considered as
waste, are processed to produce additional tequila by a process comprising
reducing the size of the leaves, mixing with water, macerating the tissue
by physical force to release sugars from the leaves, and subjecting the
leaves to alcohol fermentation, either alone or in combination with
tequila production from the piņa of the blue agave plant.

However, this does not seem to require
cooking to covert the starches (inulin) in order to convert them to fermentable sugars,
but suggests this can be done by enzymatic conversion (using inulinase
to break down inulin to fermentable sugars). However,
one study suggests, "fructans from A. tequilana Weber var. azul are
not an inulin type as previously thought."